The invention relates generally to electrical circuit protectors, such as electrical feeder circuit protectors including an electrical contactor circuit for power distribution centers employed in underground mining activities. (However, embodiments of the invention are not limited to that environment or context.) More particularly, the invention relates to apparatus which includes a contactor as well as a disconnect/grounding switch.
Carlson U.S. Pat. No. 7,277,294 titled “Contactor Draw Out Tray,” the entire disclosure of which is hereby expressly incorporated by reference, discloses electrical circuit protector apparatus which has a stationary frame and a movable frame. The stationary frame is housed within a power distribution center and has input terminals for incoming electrical power, and output terminals for delivering electrical power to equipment operating on a feeder circuit, for example equipment in the form of a mining machine including an electric motor. The movable frame is drawer-like and includes a slide-out support tray having a front panel, and may be referred to as a draw out tray. The movable frame or draw out tray carries what may broadly be described as electrical components for the electrical circuit protector, including a disconnect/grounding switch, a contactor and a controller. A particular example of electrical components for the electrical circuit protector is a motor starter. The disconnect/grounding switch is part of a mechanism which mechanically locks the movable frame relative to the stationary frame, and in particular ensures that the disconnect switch is open and the output conductors are grounded before the movable frame is drawn out of the stationary frame.
In the motor starter apparatus disclosed in Carlson U.S. Pat. No. 7,277,294, the contactor is a Jennings Vacuum contactor Model MVC77. The manually-operated disconnect/grounding switch more particularly is a knife blade disconnect/grounding switch manufactured by Line Power, a Division of Electro-Mechanical Corporation, assignee of Carlson U.S. Pat. No. 7,277,294 and of this patent document.